JP3401330B2 - Telephone - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a telephone which can be operated even during a power failure.

[0002]

2. Description of the Related Art A typical prior art is shown in FIG.
The telephone 1 is configured to include a control circuit 3 which operates in response to an input signal from the key input means 2. Electric power from the commercial AC power supply 6 is supplied to the control circuit 3 via the power supply circuit 4 and the diode 5. The control circuit 3 is composed of one IC and has a built-in dialer circuit 7 for generating a dial signal in response to an input signal from the key input means 2.

In a normal state, the control circuit 3 is energized by the commercial AC power source 6 and is kept in a standby state capable of responding to a signal from the key input means 2. In this standby state, when a dial signal is sent from the dialer circuit 7 in response to the depression of an arbitrary key on the key input means 2, the transistor 1 is responded to in response to the dialer signal.
2 is controlled, and in response thereto, the transistor 11 functioning as a dial pulse switch operates, and the dial signal is sent to the central office through the line L1.

On the other hand, during a power failure, the control circuit 3 is not energized by the commercial AC power supply 6. Therefore, when a user lifts a handset (not shown) to make a call and puts it in an off-hook state, hook switch 10 is turned on, and in response, both transistors 12 and 11 are turned on. As a result, the control circuit 3 is supplied with the electric power from the line L1 via the resistor 15 and the diode 16, and the control circuit 3 is in a standby state.

In the telephone 1 having such a configuration, the hook switch 10 is in the off state when the handset is placed (on-hook state), and the power from the line L1 is not supplied to the control circuit 3. Therefore, even if the key input means 2 is operated in the on-hook state during a power failure, the control circuit 3 does not operate, and dial transmission cannot be performed. Therefore, in order to cope with a power failure, as shown in FIG. 6, there has been proposed a phone 21 in which a dialer circuit 22 for a power failure is separately attached to the configuration of the phone 1 as described above.

The configuration of the telephone 21 will be described with reference to FIG. The same components as those of the telephone 1 shown in FIG. 5 are designated by the same reference numerals. Dialer circuit 22 for power failure
Is connected to the line L1 via the resistor 23 and the diode 24.
It is possible to supply power from. The power failure dialer circuit 22 has a circuit configuration capable of operating even at 1 μA or less in the standby state. The resistance value of the resistor 23 is required to be set to a magnitude of 1 MΩ or more according to the standard of the line L1. Therefore, the resistance 23
The current that can be supplied to the device is about several tens of μA. For example, if the voltage of the line L1 is 48V and the resistance value of the resistor 23 is 1 MΩ, the current flowing through the resistor 23 is 48V.
It becomes about μA, which is a current at which the power failure dialer circuit 22 can sufficiently operate.

On the other hand, since the control circuit 3 is always in a standby state, an operating current of 200 to 300 μA or more is required. Therefore, the control circuit 3 has the resistance 23
The control circuit 3 cannot be directly connected to the line L1 because it does not operate depending on the power supply voltage supplied from the line L1 via the line L1. The power failure dialer circuit 22 is normally supplied with a power supply voltage of about 5 V from the commercial AC power supply 6 through the power supply circuit 4.

In the telephone 21 having such a structure, even when a power failure occurs, power is supplied to the dialer circuit 22 for power failure from the line L1 through the resistor 23, so that a signal from the key input means 2 is received. It will be in a standby state. Therefore,
Even in the on-hook state, the dial input can be performed by operating the key input means 2.

[0009]

[Problems to be Solved by the Invention] Such a telephone 21
So, even if there is a power outage, you can make a dial call in the on-hook state, but for this reason, another I
It is necessary to provide a power failure dialer circuit 22 dedicated to power failure, which is composed of C, and there is a problem that the number of parts of the telephone itself increases, including other configurations related to the power failure dialer circuit 22 .

Therefore, it is conceivable that the dialer circuit can be energized even in the event of a power failure by providing a switch circuit for closing the line in response to the operation of the key input means. Then, the line may be closed against the intention of the user due to a malfunction of the key input means. In addition, the line may be closed due to external noise, noise in the system, etc. regardless of the user's intention. In such a case, there arises a problem that an incoming call cannot be made from the other party.

An object of the present invention is to solve the above problems and to provide a telephone capable of preventing line closure due to malfunction or the like when dialing is made in an on-hook state.

[0012]

According to the present invention, there is provided a key input means, a dialer circuit for sending a dial signal to a line in response to an input signal from the key input means, and an on-hook state for opening the line. A hook switch for selectively setting an off-hook state for closing the line, and a switch circuit for closing the line in response to an operation of a predetermined switch when dialing in the on-hook state,
A switching transformer that receives the output of the switch at its input.
And register, receives an input the output of said switching transistor, and the dial pulse switch to be turned on during the off-hook condition, the line by the switching circuit closing
When connected, connect the switch circuit to the dialer circuit.
A circuit for determining whether or not the predetermined switch is operated through the power supplied through the circuit and a line for responding to the output from the determination circuit and opening the line when the predetermined switch is not operated. an open circuit, given the output of the determination circuit, and a microprocessor that controls the dialer circuit and the line open circuit, the dialer times
Path, the line release circuit, the determination circuit, and the micro
And a microprocessor.
And a control circuit controlled by a sessa .

Further, according to the present invention, key input means, a dialer circuit for sending a dial signal to a line in response to an input signal from the key input means, an on-hook state for opening the line, and closing the line. A hook switch for selectively setting an off-hook state to be connected, a switch circuit for closing the line in response to operation of a predetermined switch when dialing in the on-hook state, and the switch.
A switching transistor that receives the output of H
When the dial pulse switch that receives the output of the switching transistor as an input and is turned on in the off-hook state and the line is closed by the switch circuit, power is supplied to the dialer circuit through the switch circuit and the predetermined A determination circuit that determines whether a switch has been operated, a line opening circuit that responds to the output from the determination circuit, and opens the line when the predetermined switch is not operated, and an output from the determination circuit In response to this, when the predetermined switch is operated, the switching transistor holds the ON state in order to maintain the closed state of the line, and the output of the determination circuit is given to the line open circuit and the dialer. A microprocessor for controlling a circuit, the dialer circuit, the line opening circuit, and Wherein the judgment circuit has a microprocessor is provided, and a telephone which comprises a control circuit controlled by the microprocessor.

[0014]

According to the invention of claim 1, when the predetermined switch is operated when dialing is made in the on-hook state, the switch circuit responds to the operation of the predetermined switch to close the line. As a result, the power from the line is transferred to the dialer.
Is supplied to the circuit, the dialer circuit is power energized.

When closing the line in this way, if the predetermined switch is not operated, the judgment circuit judges that this is an abnormal operation, and the line opening circuit opens the line. That is, when closing the line, if the predetermined switch is not operated, the line closed state can be released once and the line can be closed again.

According to the second aspect of the present invention, when the predetermined switch is operated during dialing in the on-hook state, the switch circuit responds to the operation of the predetermined switch to close the line. This allows the power from the line to
The dialer circuit is supplied with electric power to the dialer circuit. When closing the line in this way, if the predetermined switch is operated, the judgment circuit judges that this is normal, and the ON state of the switching transistor is maintained.
Lifting and holds the circuit closing state. On the other hand, when the predetermined switch is not operated, the determination circuit determines that this is an abnormal operation, and the line release circuit opens the line.

[0017]

1 is a block diagram showing the electrical construction of an embodiment of the present invention. The telephone 31 has a key input means 32.
From the input signal to the control circuit 33 which operates in response to the input signal. A commercial AC power supply 36 is connected to a power supply input terminal VDD of the control circuit 33 via a power supply circuit 34 and a diode 35. The control circuit 33 is composed of one IC and has a dialer circuit 37 for generating a dial signal in response to an input signal from the key input means 32. The dialer circuit 37 is connected to the line L1 via the resistors 55 and 38 and the hook switch 39. A transistor 41 that functions as a dial pulse switch is connected to the line L1, and a switching transistor 42 that performs a switching operation in response to a dial signal from the dialer circuit 37 is connected to the base of the transistor 41 via a resistor 43. To be done.

On the other hand, the line L1 is connected to the base of the transistor 42 via a resistor 51, a diode 52, a transistor 53, and a resistor 54. The key input means 32 has an off-hook dial key (O
Decoder 50 that operates in response to an HD key 56)
Is provided, and the transistor 53 is on / off controlled by the output from the decoder 50. The decoder 50 includes the resistor 51 and the diode 52.
The power supply voltage from the line L1 is applied via the. The line L1 is connected to the power supply input terminal VDD of the control circuit 33 via the resistor 45 and the diode 46.

The control circuit 33 includes a line opening circuit 61 for opening a closed line, a judgment circuit 70 for judging whether or not the OHD key 56 is pressed, and the control circuit 3.
A microprocessor 71 is provided to control the overall operation of 3. The output of the judgment circuit 70 is given to the microprocessor 71. The dialer circuit 37 and the line opening circuit 61 are configured to operate in response to the output of the microprocessor 71. The output from the line opening circuit 61 is used as a hook switch signal by the decoder 50.
Given to.

The control circuit 33 is normally energized by the commercial AC power supply 36, and the key input means 32 is provided.
It is held in a standby state capable of responding to the signal from. When an arbitrary telephone number is pressed in the key input means 2 in this standby state, a dial signal is sent from the dialer circuit 37 in response to this. The transistor 42 operates in response to the dial signal, the transistor 41 is turned on / off in response to this, and the dial signal is sent to the telephone station via the line L1.

On the other hand, at the time of a power failure, the control circuit 33 is not energized by the commercial AC power source 36, so that it does not operate as it is. However, when the user attempts to make a call and lifts the handset (not shown) to put it in the off-hook state, the hook switch 39 is turned on, and in response thereto, the transistors 42 and 41 are both turned on and the line L1 is closed. Tied up. As a result, the control circuit 33 is supplied with the electric power from the line L1 via the resistor 45 and the diode 46, and the control circuit 33 can be placed in a standby state. Thus, the resistance 45
An electric power supply means for the control circuit 33 is configured by including the diode 46 and the diode 46.

The resistance value of the resistor 45 is
-The voltage between the diodes 46 is set to 2-3V. On the other hand, in the normal state, the voltage supplied from the power supply circuit 34 is set to about 5V. Therefore,
When power is supplied to the control circuit 33 through the diode 35 in a normal state, even if the transistor 41 is turned on, the voltage between the resistor 45 and the diode 46 is higher than the voltage on the cathode side of the diode 46. Therefore, the voltage from the line L1 is not supplied to the control circuit 33 .

Next, the case where the telephone 31 is operated in the on-hook state at the time of power failure will be described. First, in this state, the hook switch 39 is off and the line L
1 is kept open. Therefore, the control circuit 33 is not supplied with power from the line L1. on the other hand,
At the time of a power failure, the control circuit 33 is not supplied with power from the power supply circuit 34, so that the control circuit 33 does not operate and does not enter the standby state.

Therefore, in this state, by pressing the OHD key 56 of the key input means 32, the control circuit 33 can be put in a standby state. That is, O
When the HD key 56 is pressed, the transistor 53 is turned on via the decoder 50, and the power supply voltage from the line L1 is given to the base of the transistor 42 via the resistor 51, the diode 52, the transistor 53, and the resistor 54. To be As a result, the transistors 42 and 41 are both turned on, and the line L1 is closed. Therefore, the control circuit 33 includes the resistor 45 and the diode 46.
The electric power from the line L1 is supplied through the control circuit 33 and the control circuit 33 enters the standby state.

By pressing the OHD key 56, the control circuit 33
Is set to the standby state, the determination circuit 70 determines that the OHD key 56 is pressed. The microprocessor 71 detects this and outputs a signal for holding the line closed through the dialer circuit 37, holds the ON state of the transistor 42, and holds the closed state of the line L1. After that, the microprocessor 71 controls the decoder 50 through the line opening circuit 61 to prohibit the input from the key input means 32. As a result, the closed state of the line L1 can be maintained independently of the operation of the key input means 32. In this case, the dialer circuit 37 and the microprocessor 71 are included in the circuit closing and holding circuit.

FIG. 2 is a block diagram showing the configuration around the decoder 50, and FIG. 3 is a block diagram showing the configuration around the determination circuit 70. As shown in FIG. 2, the decoder 50 is composed of a NOR gate G1 and a NAND gate G2. For the OHD key 56 of the key input means 32, the lines A and H held at the L level are
A line B held at the level is connected, and the lines A and B are inputs to the gate G1.

On the other hand, the line open circuit 61 is configured to include a resistor 63 and a transistor 64 provided between a power source 62 and a ground line, as shown in FIG.
A hook switch signal is derived from between the resistor 63 and the transistor 64. The determination circuit 70 is a circuit for determining the depression of the OHD key 56 among the 8-bit input signals from the key input means 32. In the present embodiment, for example, the input signal when the OHD key 56 is depressed is “111011”.
The case of setting "10" will be described.

The decision circuit 70 is provided with eight exclusive OR circuits (hereinafter referred to as EX-OR circuits) 81 to 88 corresponding to each bit of the input signal and outputs from the EX-OR circuits 81 to 88. It is composed of an 8-input NAND circuit 90, and an input signal from the key input means 32 is an OHD key 56.
NAN only when "11101110" corresponding to pressing
The output of the D circuit 90 becomes L level, and the output of the NAND circuit 90 becomes H level for other input signals.

As described above, in the determination circuit 70, when the OHD key 56 is pressed, the output of the NAND circuit 90 becomes L level, so the transistor 64 of the line opening circuit 61 is turned on, and the hook switch signal changes from H level to L level. It becomes a level. On the other hand, when any key other than the OHD key 56 is pressed,
Alternatively, when none of the keys is pressed, the output of the NAND circuit 90 becomes H level, so the line release circuit 61
Transistor 64 is turned off, and the hook switch signal is set to the H level.

The output of the gate G1 and the hook switch signal from the line open circuit 61 are applied to the gate G2, and the output of the gate G2 is applied to the transistor 53. The power supply 65 that holds the line B at the H level in the key input means 32 and the power supply 62 of the line open circuit 61 are both connected to the connection point D between the diode 52 and the transistor 53 ( (Not shown), power is supplied from the line L1 together with the decoder 50 described above. Therefore, the key input means 32, the decoder 50, and the line opening circuit 61 can be kept in an operable state even during a power failure without separately providing a backup power source such as a charging circuit and a battery.

In such a structure, when the OHD key 56 is not pressed in the on-hook state, the line A is at the L level and the line B is at the H level, so that the output of the gate G1 is at the L level. On the other hand, since the hook switch signal is at the H level and the output of the gate G1 is at the L level, the output of the gate G2 is at the H level and the transistor 53 is turned off. Therefore, in this state, the line L1 is kept open.

FIG. 4 is a flow chart for explaining the operation of the telephone 31 in the on-hook state at the time of power failure. In step S1, when the OHD key 56 is pressed, the line B becomes L level, so that the output of the gate G1 becomes H level. At this time, since the switching signal is held at the H level, the gate G
The two outputs become L level (step S2).

As a result, in step S3, the transistor 53 is turned on, and the transistor 4 is turned on.
The line L1 is closed via 2, 41. Step S4
Then, power is supplied from the closed line L1 to the control circuit 33 through the resistor 45 and the diode 46,
The control circuit 33 operates and enters a standby state.

In step S5, the determination circuit 70 determines whether or not the OHD key 56 has been pressed in step S1. If it is determined that the OHD key 56 is pressed, step 6 is executed.
Proceed to. In step S6, the microprocessor 7
1 controls the dialer circuit 37 in response to the output of the determination circuit 70, and outputs a signal for holding the line closed. As a result, the transistors 42, 41 are kept in the ON state and the line L1 is kept in the closed state. Thus, in step S6, the closed state of the line L1 can be maintained regardless of the operation from the key input means 32, that is, independently of the operation of the key input means 32.

In step S7, the microprocessor 71 responds to the output of the judgment circuit 70 to turn on the transistor 64 of the line open circuit 61 and set the hook switch signal to L level. Therefore, regardless of the output of the gate G1, the output of the gate G2 becomes H level, and the transistor 53 is turned off. As a result, the line closing by the transistor 53 is stopped (step S8). . If the hook switch signal is set to the L level in this way, the key input means 32
The closed state of the line L1 can be maintained independently of the operation of. Therefore, the operation of the telephone 31 is not affected by the decoder 50, the transistor 53, etc.
Malfunctions can be prevented.

The duration of pressing the OHD key 56 is usually several hundred msec. On the other hand, the time required from the control circuit 33 being in the standby state in step S4 until the circuit 53 is closed by the transistor 53 in step S8 is several tens of msec. Therefore, in reality, the processes from the pressing of the OHD key 56 in step S1 to step S8 are performed while the pressing of the OHD key 56 is continued.

In step S9, normal processing operation is performed. That is, dialing is performed by inputting an arbitrary telephone number in the key input means 32.
When the call ends, the line L1 is opened by deriving an L level dial signal from the dialer circuit 37 in step S10. When the determination circuit 70 determines in step S5 that the OHD key 56 is not pressed, the process proceeds to step 11.

In step S11, the microprocessor 71 responds to the output of the judgment circuit 70 to turn on the transistor 64 of the line open circuit 61 without holding the line closed state by the dial signal, The hook switch signal is set to L level. Therefore, regardless of the output of the gate G1, the output of the gate G2 becomes H level, and the transistor 53 is turned off. As a result, the line L1 which was once closed in step S3 is opened (step S12).

Even if the line L1 is erroneously closed by pressing a key other than the OHD key 56, the line L1 can be immediately opened by detecting it through the determination circuit 70. For example, if the line-closed state continues due to the above-mentioned malfunction, a problem may occur in that the other party cannot receive an incoming call. However, in the present invention, the line L1 can be immediately opened, so that the reliability of the line-closed operation is high. Can be increased.

Further, even if the line is closed due to external noise, noise in the system, etc., the OHD key 56 in the decision circuit 70 will be closed regardless of the user's intention.
Since it is not possible to detect the pressing of the line, the line can be immediately opened via the line opening circuit 61. The decoder 50 may be configured by a simple external component, or may be built in the IC configuring the control circuit 33 and the like. Further, instead of the OHD key 56, a switch may be separately provided in addition to the key input means 32, and the decoder 50 may be controlled by operating the switch.

In the present embodiment, the control circuit 33 has been described as a telephone set which is normally energized by the commercial AC power supply 36, but the commercial AC power supply is not provided.
It can also be applied to telephones that are originally powered by lines.

[0042]

As described above, according to the invention of claim 1,
When the line is closed by the key input means, the line is opened when a predetermined switch is not operated, and a malfunction can be prevented. That is, even if the line is closed against the user's intention due to a malfunction or noise, the line can be opened, so that the reliability of the line closing operation can be improved.

According to the second aspect of the invention, when the line is closed by the key input means, the line closed state can be maintained only when a predetermined switch is operated, and a malfunction can be prevented. That is, even if the line is closed due to a malfunction or noise against the intention of the user, the line can be opened as long as the predetermined key is not operated. You can improve your sex.

[Brief description of drawings]

FIG. 1 is a block diagram showing an electrical configuration of an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration around a decoder 50.

FIG. 3 is a block diagram showing a configuration around a determination circuit 70.

FIG. 4 is a flowchart for explaining a line opening operation.

FIG. 5 is a block diagram showing an electrical configuration of a conventional technique.

FIG. 6 is a block diagram showing an electrical configuration of another conventional technique.

[Explanation of symbols]

32: Key input means 33 ... Control circuit 36 ・ ・ ・ Commercial AC power supply 37 ・ ・ ・ Dialer circuit 39 ... Hook switch 41, 42, 53 ... Transistor 50 ... Decoder 56 ・ ・ ・ OHD key 64 ・ ・ ・ Circuit open circuit 70 ... Judgment circuit 71 ・ ・ ・ Microprocessor

Claims (2)

(57) [Claims] 1. A key input unit, a dialer circuit for sending a dial signal to a line in response to an input signal from the key input unit, an on-hook state for opening the line, and an off-hook state for closing the line. And a switch circuit for selectively setting the switch, a switch circuit that closes the line in response to the operation of a predetermined switch when dialing in the on-hook state, and a switching transistor that receives the output of the switch as an input.
And register, receives an input the output of said switching transistor, and the dial pulse switch to be turned on during the off-hook condition, when said line goes閉結by said switching circuit, power is provided through the switching circuit to the dialer circuit
A determination circuit that determines whether or not the predetermined switch has been operated, and a line opening circuit that responds to an output from the determination circuit and opens the line when the predetermined switch is not operated, A microprocessor that receives the output of the determination circuit and controls the line opening circuit and the dialer circuit, the dialer circuit, the line opening circuit, and the determination circuit.
And the microprocessor is provided, and
And a control circuit controlled by a microprocessor . 2. A key input unit, a dialer circuit for sending a dial signal to a line in response to an input signal from the key input unit, an on-hook state for opening the line, and an off-hook state for closing the line. And a switch circuit for selectively setting the switch, a switch circuit that closes the line in response to the operation of a predetermined switch when dialing in the on-hook state, and a switching transistor that receives the output of the switch as an input.
And register, receives an input the output of said switching transistor, and the dial pulse switch to be turned on during the off-hook condition, when said line goes閉結by said switching circuit, power is provided through the switching circuit to the dialer circuit
A determination circuit that determines whether or not the predetermined switch has been operated, and a line opening circuit that responds to an output from the determination circuit and opens the line when the predetermined switch is not operated, In response to the output from the judgment circuit, when the predetermined switch is operated, the switching transistor holds the ON state to maintain the closed state of the line, and the output of the judgment circuit is given, A line opening circuit and a microprocessor for controlling the dialer circuit , the dialer circuit, the line opening circuit, and the determination circuit
And the microprocessor is provided, and
And a control circuit controlled by a microprocessor .